PSIII-1 Characterization of eating pattern and animal behavior according to productive system of intensive beef fattening fed high-concentrate diets

Abstract

Abstract Eating pattern and animal behavior of three different intensive beef fattening systems, combining cattle breed, gender, and fattening days were studied under the same commercial farming conditions. A total of 120 animals were allocated in 6 pens (two per treatment), and each pen was assigned to 1 of 3 treatments according to productive system: 1) Holstein bulls, slaughtered at 11.5 months of age (142 ± 3.3 days of age and 176 ± 5.5 kg of initial BW), 2) crossbred heifers at 10 months (141 ± 3.3 days of age and 165 ± 5.5 kg of initial BW), and, 3) crossbred Angus bulls at 12.5 months (154 ± 3.3 days of age and 192 ± 5.5 kg of initial BW). Each pen had two separate feeders for concentrate and straw, and a water trough. Eating pattern was recorded per day and animal, and animal behavior was analyzed fortnightly by scan pen sampling. Data were analyzed using a mixed-effects model with repeated measures. Most relevant interaction revealed that around 215 days of age (onset of puberty) heifers visited less frequently the feeder (7.5 vs 8.1 ± 0.23) and devoted more time to eat (7.5 vs 6.5 ± 0.22 min), decreasing eating rate (153.8 vs 177.4 ± 4.97 g/min) compared with bulls. Regardless of age, heifers tended (P < 0.10) to exhibit more frequently non-agonistic (20.4 vs 13.0 ± 1.53 n/15 min), less agonistic (1.2 vs 3.8 ± 0.92 n/15 min) and sexual (1.3 vs 5.5 ± 1.65 n/15 min) behaviors, and more stereotypies (1.5 vs 0.3 ± 0.08 n/15 min) compared with bulls. In conclusion, when animals spent time performing agonistic and sexual behaviors, the time devoted to eat was reduced, identifying a gender effect. This finding could have implications in terms of feeder design, number of feeding spaces, and feeder access.